Inherently rigid instrument carrier assembly

ABSTRACT

The invention relates to an inherently rigid instrument carrier assembly that is used as a structural or styling element, in particular in motor vehicles. Said assembly replaces the support mounts that conventionally run between support elements, such as the A-pillars of a motor vehicle. The inventive assembly comprises a molded part configured as an upper shell and a molded part configured as a lower shell, consisting of fibre-reinforced thermoplastic, which is formed, in particular in a deep-drawing process, into the structure of the upper shell and the lower shell, producing at least one respective reinforcement profile that extends in the longitudinal direction of the molded part, i.e. between the support elements. Said reinforcement profile comprises at least one respective substantially vertical strut and at least one tranversal limb extending transversally to said strut. The vertical struts of the shells in particular are used to connect the two molded parts, in particular by means of plastic welding.

The invention relates to an inherently rigid instrument holder assembly,particularly one that serves as a structural or styling element, of thetype mentioned in the preamble of claim 1.

A device of this type, serving as an instrument panel or carrier, isalready known (EP 0 662 900 B1), which consists of a profiled part thatextends in its longitudinal direction, and can be connected with supportelements, for example the A pillars of a motor vehicle, at theirlongitudinal ends. The instrument panel serves to accommodateinstruments, displays, radio, glove compartment, airbag, and steeringcolumn with the related instrument systems. In this connection, thisknown device consists of fiber-reinforced thermoplastic plastic, such asfiberglass-filled polyurethane, which is brought into the profiled andstructured shape using the so-called SRIM technology, by means ofinjection molding. It has been shown that aside from difficulties duringreactive injection molding, a relatively great material requirement isnecessary in order to achieve sufficient structural stability of thedevice with regard to bending and twisting (torsion), particularly bymeans of load introduction by way of the steering column.

Furthermore, it is also known (EP 0 083 701 A2) to structure aninstrument panel carrier of several individual parts, each of which hasbeen formed using thermoplastic material, by means of injection moldingor transfer molding. In this connection, several structural parts areconnected with one another in such a manner that they form a carrier inwhich two outer parts follow a center part; the modular series comprisedof the two outer parts and the center part forms the total carrier. Inorder to avoid or reduce vibrations of the individual parts as much aspossible, a thin foam material layer is laid between the individualparts, in each instance. This multi-segment carrier is also not entirelysatisfactory.

The invention is based on the task of improving an inherently rigiddevice of this type in such a manner that the carrier is so inherentlyrigid and structurally stable, in and of itself, without additionalsupport carriers between the support elements of a motor vehicle, forexample, that it withstands stress, even that caused by the applicationof force to the steering column, without impairing its function, andfurthermore guarantees the requirements of safety technology, and can beproduced with the lowest possible material requirement and lowproduction costs. Good disposability is also desirable.

The invention is characterized in claim 1 and preferred embodiments areclaimed in the dependent claims. Furthermore, additional improvements ofthe invention are evident from the drawing and the followingdescription; the right to claim these in additional claims is reserved.

The principle of the invention provides that the bearing and supportingparts are formed in the form of two molded parts, an upper shell and alower shell, which essentially consists of organic sheet material.“Organic sheet material” is understood to mean a further development ofthe GMT (fiberglass mat reinforced thermoplastic) technology. This isunderstood to mean semi-finished products made of thermoplastic plastic,in the form of strips or panels, having fiber reinforcements,particularly in the form of woven fabrics, but also non-woven fabrics or2D or 3D textiles, which can be deformed, particularly when heated.

Both molded parts have at least one reinforcement rib that extends intheir longitudinal direction, i.e. in the direction between the supportelements, for example the A pillars of a motor vehicle. Thereinforcement rib has at least one vertical ridge that is essentiallyvertical, and at least one crosswise shank that extends essentiallyperpendicular to it. It has been shown that this profiling of thereinforcement rib makes an outstanding contribution to the reinforcementof the molded parts.

Furthermore, at least one of the shells can be connected with at leastone reinforcement rib made of plastic. In this connection, it isrecommended to use the same thermoplastic plastic, particularly the samefiber-reinforced plastic, as for the organic sheet material.

It is practical if the connection between the upper shell and the lowershell, i.e. the two molded parts, is made along the reinforcement rib,over its area, specifically along the vertical ridges of the latter. Inthis connection, bonding is recommended, particularly using the frictionbonding method, in which the surface of the thermoplastic melts due toheating that occurs during friction, and as a result, the two verticalridges that were contacted with one another are firmly connected withone another after cooling.

In accordance with another embodiment of the invention, it isrecommended to add either an additional vertical shank at the crosswiseshanks, to form a U profile, or an additional crosswise shank at thevertical ridge, to form a T or I profile. The deep-drawing method of thesemi-finished product consisting of organic sheet material is alsorecommended for shaping these profiled reinforcement ribs.

The vertical ridge of the reinforcement rib can also serve to attachtunnel supports.

For the attachment of additional elements, or attachment on additionalelements, and for the guidance of units, such as a radio receiver or amobile telephone, attachment or guide elements made of plastic can beattached to the upper shell and/or the lower shell, using the injectionmolding method or the transfer molding method.

It is also possible to configure reinforcement ribs as a deformationelement, which deform when specific forces occur, and then also permitdeformation of the shell part in question.

Furthermore, according to a special embodiment of the invention, it ispractical to provide the upper shell with a planned breaking line at theinstallation location of an airbag, so that this part of the upper shellserves as an integrated airbag lid that tears open along the plannedbreakage line when the airbag is triggered. This line can be formed by apre-finished organic sheet material region. However, it is also possibleto use a pre-cut part (tailored blank) in which at least approximately90% of the reinforcement fibers or reinforcement filaments of the wovenfabric run in the longitudinal direction of the vehicle, in other wordscrosswise to the longitudinal direction of the molded part, while theregion of the organic sheet material around the tailored blank has atleast one woven fabric layer having approximately the same number ofwarp and weft threads.

The use of organic sheet materials also makes it possible to finishthem, during the production of the semi-finished products, in such amanner that certain regions are less rigid than others, so that underpressure, deformable regions form, in order to better absorb the impactof body parts of passengers.

Furthermore, it is also possible to form regions, particularlyline-shaped regions, of the organic sheet material as a “hinge,” so thatupon impact, pivoting or bending of the adjacent region along a definedline is made possible. The hinge formation is achieved by means of aparticular sizing of the woven fabric reinforcement with reference tothe plastic.

The upper shell, in particular, is provided with scoops and/or grooves,thereby creating storage spaces or tray areas and/or making constructionspaces for accommodating instrument panel components available. For theaccommodation of decorative strips or storage compartments that can beopened, the upper shell edge facing the passengers should have cut-outsin the organic sheet material that are supported with injection-moldedribs, in the form of ridges.

According to a particular embodiment of the invention, the upper shellis provided with depressions to accommodate the airbag module both onthe driver's side and on the front passenger's side. Furthermore, it isalso advantageous if the upper shell is provided with a scoop that canbe bonded on, both on the driver's side and on the front passenger'sside, so that the arrangement of the steering column and the frontpassenger's airbag can be re-fitted, in simple manner, for the motorvehicles to be used in Great Britain, for example, for left-sidetraffic. This results in RD/LD symmetry (right-side driver/left-sidedriver).

It is understood that the upper shell, and the lower shell, ifnecessary, can be provided with a covering on the surface facing thepassengers, in order to produce specific color or structural effects,whereby reflections are reduced and esthetic aspects can be better takeninto consideration, for example. Such an individually selected coveringmakes it possible to always use the same material for the organic sheetmaterial, in order to thereby run production in more cost-effective andenvironmentally friendly manner, independent of special customerrequests.

Such covering can, as is known, also be filled with foam material, whichnot only improves the optical properties but also serves as impactprotection, or actually allows certain spots to be pressed in, forexample during assembly. PUR foam, for example, which is covered with athin skin on the surfaces facing the passengers, is particularlysuitable for this purpose, and for this reason, such a covering materialis also referred to as an “integral foam.”

The molded parts formed according to the invention, made offiber/plastic laminate, together with the reinforcement ribs set ontothem, then form a so-called “FPL hybrid” consisting of the originalsheet-like woven fabric reinforced plastic semi-finished product, whichis deformed to produce the desired 3D contour, using a process derivedfrom deep-drawing of metals, and then completed with LFT injectionmolded components that are injection-molded on or bonded on.

The production of organic sheet material can take place using autoclavesand/or double-belt presses, so that specially produced semi-finishedproducts having regions of differing rigidity or strength can beproduced by variations, for example of the type of woven fabric (numberof looping points, thread diameter, number of threads in the warp andweft direction) and the number of woven fabric layers between films ofplastic polymer (local change in thread density or fiber volumecontent).

The invention therefore offers an instrument panel that takes over thesupport function between the A pillars, according to the principle of aflowing surface contour, with depressions instead of bores and across-section combination of reinforcement ribs having a T or U hollowprofile, in particular, having great structural strength and rigidity.

Exemplary embodiments of the invention will now be discussed using thedrawing. This shows:

FIG. 1, in a side view, an upper shell 1 with a lower shell 3 and atunnel support 2;

FIG. 2, a top view of an upper shell 1 clamped between the supportelements 4, to which shell two tunnel supports 2 are attached, which aresupported on the car body tunnel 5;

FIG. 3, the top la of the upper shell 1, and

FIG. 4, the top of the lower shell 3;

FIG. 5, a three-segment controller unit;

FIG. 6, a schematic cross-section through the assembly that serves asthe carrier for instruments and, under some circumstances, other units;

FIG. 7, a partial cross-section through a reinforcement rib;

FIG. 8, a schematic representation of the woven fabric reinforcement andtailored blank of the upper shell, and

FIG. 9, a partial cross-section through an air channel.

According to FIG. 1, the assembly serving as an instrument panel or asan instrument carrier consists of the upper part 1 and the lower part 3,specifically along reinforcement profiles 6 and 7 that are onlyindicated schematically here, each of which has a vertical ridge 31,according to the example in FIG. 7, from which ridge crosswise shanks31a project approximately at a right angle, i.e. horizontally.

A scoop 13 is set into the recess 41 shown in FIG. 2, in such a mannerthat its hood-like upper part rises above the surface of the upper shell1, in an upward direction.

Furthermore, the upper shell 1 and the lower shell 3 have areinforcement rib 32 and 33, the cross-shaped structure of which is evenbetter evident in FIG. 4, namely from the top of the lower shell 3.

The upper shell 1 is deep-drawn from the organic sheet material, in sucha manner that not only the aforementioned reinforcement profile 6 and,if applicable, reinforcement ribs on the inside, but also trough-shapeddepressions 14, 15, 16 are formed, of which the trough-shaped depression17 can be used to accommodate an airbag element. On the upper shell 1,guide elements 18 are furthermore disposed on the edge facing thepassengers, which can serve to attach additional units.

The lower shell 3 of FIG. 4 is provided with load introduction elements20 at the ends, which can be used for attachment to the support elements4 or A pillars. In the vicinity of these load introduction elements 20,in the region of the ends of the vertical ridge 31, guide rails 35 aredisposed to accommodate controller units 22 or electrical/electronicunits.

According to FIGS. 4 and 7, a segmented controller unit is housed in thecavity of the inherently rigid instrument holder assembly, the segments10 of which unit are connected with one another, in pivoting manner, bymeans of hinge joints 57, so that if service for theelectrical/electronic unit, for example, is required, access is possiblewith the vehicle door open and without disassembly of the cockpit moduleor the inherently rigid instrument holder assembly.

It is understood that lines can also be integrated into the instrumentpanel or instrument carrier.

According to FIG. 8, a cavity is formed by the ridges 23 and 24 moldedonto the upper shell 1 and the lower shell 3, which cavity can be usedas an air guide, for example.

In FIGS. 6 and 7, the progression of the organic sheet material formedto produce reinforcement profiles 6, 7 is shown schematically, therebyforming a type of T at the top and a type of U and T, in cross-section,at the bottom. The organic sheet material of polypropylene or polyamide,for example, is reinforced with a woven fabric insert 12 of fiberglassor carbon fiber woven fabric.

According to FIG. 9, a woven fabric reinforcement 12 of inorganic and/ororganic fibers of the thermoplastic organic sheet material, formed toproduce the upper shell 3 can be seen schematically. Instead of thewoven fabric shown in the drawing, any 2D or 3D textiles as well asnon-woven fabrics in many different combinations can be used. Here,special pre-cut parts 12 a, 12 b (tailored blanks) can form defineddeformation regions 59 or break-up lines 58 for fulfilling safetytechnology requirements, particularly when using textiles having fibercomponents 12 b oriented predominantly in the longitudinal vehicledirection.

1. (canceled)
 2. The assembly as recited in claim 23, wherein theorganic sheet material comprises a thermoplastic reinforced with a fiberwoven fabric.
 3. The assembly as recited in claim 2, wherein the atleast one reinforcement rib is formed from the same thermoplastic as theorganic sheet material.
 4. The assembly as recited in claim 20, whereinsaid at least one strut comprises a plurality of substantially verticalstruts connecting the upper shell and the lower shell with one another.5. The assembly as recited in claim 4, wherein the upper shell is bondedor melted to the lower shell.
 6. The assembly as recited in claim 5,wherein the bonding of the upper shell to the lower shell takes place byway of friction bonding.
 7. The assembly as recited in claim 23 furthercomprising tunnel supports attached to the vertical strut.
 8. Theassembly as recited in claim 20 further comprising attachment elementsor guide elements made of plastic and molded onto the upper shell or thelower shell by injection molding or transfer molding.
 9. The assembly asrecited in claim 21, wherein said at least one reinforcement ribcomprises a plurality of deformation elements, which deform when forcesoccur and then also permit deformation of a corresponding shell part.10. The assembly as recited in claim 20, wherein the upper shell isprovided with scoops or depressions for forming storage spaces or trayspaces or for accommodating instrument panel components, airbag modules,loudspeakers, or similar instrument panel parts.
 11. The assembly asrecited in claim 23, wherein the upper shell has an upper shell edgethat faces the passengers, said upper shell edge having ridge-shapedcut-outs, supported with injection-molded ribs, in the organic sheetmaterial, to accommodate decorative strips or storage compartments thatcan be opened.
 12. The assembly as recited in claim 2, wherein the uppershell has depressions to accommodate an airbag module both on thedriver's side and the front passenger's side.
 13. The assembly asrecited in claim 20, wherein a scoop is bonded onto the upper shell onthe driver's side.
 14. The assembly as recited in claim 12, wherein theupper shell follows the depression formation at the installationlocation of the airbag, and is provided with a planned tear-open seam ofthe integrated airbag lid.
 15. The assembly as recited in claim 14,wherein the planned tear-open seam is formed by a pre-finished organicsheet material region.
 16. The assembly as recited in claim 14, whereinsaid at least two molded parts are substantially formed from organicsheet material and the planned tear-open seam (58) is formed by apre-cut tailored blank in which at least approximately 90% of thereinforcement fibers or reinforcement filaments of the woven fabric runcrosswise to the longitudinal direction of the molded part, while theregion of the organic sheet material around the tailored blank has atleast one woven fabric layer having approximately the same number ofwarp and weft threads.
 17. The assembly as recited in claim 23, whereinthe upper shell has planned tear-open locations or regions that aredeformable under pressure, in order to absorb the impact of body partsof passengers.
 18. The assembly as recited in claim 17, wherein organicsheet material regions of the upper shell comprise woven fabric hingesthat permit pivoting or bending of the adjacent region in case of animpact.
 19. The assembly as recited in claim 20, wherein the top of atleast the upper shell, facing the passengers, is provided with acovering that has a plastic foam material at least in certain regions.20. An instrument holder assembly comprising at least two molded partsfor attachment to support elements of a motor vehicle, said at least twomolded parts comprising an upper shell and a lower shell, each of saidupper shell and said lower shell comprising at least one respectivereinforcement profile comprising at least one strut and at least onetransverse limb extending transversely to said strut.
 21. The assemblyas recited in claim 20 further comprising at least one reinforcement ribprovided on a member selected from the group consisting of said uppershell and said lower shell.
 22. The assembly as recited in claim 20wherein said at least two molded parts are formed from fiber-reinforcedplastic.
 23. The assembly as recited in claim 21 wherein: said at leasttwo molded parts are substantially formed from organic sheet materialwhich is shaped by a deep-drawing process into said upper shell and saidlower shell; said at least one respective reinforcement profile extendsin a longitudinal direction of the corresponding molded part; said atleast one strut comprises a vertical strut extending substantiallyvertically; and said at least one reinforcement rib is formed fromfiber-reinforced plastic.